Method of manufacturing base terminals of a miniature incandescent light bulb

ABSTRACT

The specification describes a method for the attachment of contact members, held in a base, with electrodes passing through the glass envelope of a miniature incandescent lamp. In accordance with the method the contact members are strips of electrically conducting material which are introduced from below through recesses in the bottom of the upper part of the base until the strips reach the upper rim of the base and are electrically connected with the electrodes. Following this with the introduction of the glass envelope in the hollow cylindrical upper part of the base the strips are drawn back. At their free lower ends they are severed and are fixed to the lower part of the base.

United States Patent Palmen 1 Apr. 2, 1974 [54] METHOD OF MANUFACTURING BASE 3,548,243 12/1970 Magherini 313/315 x TERMINALS OF A MINIATURE 3,619,598 11/1971 Hermanson 240/10 T INCANDESCENT LIGHT BULB lnvcntor: Otto Palmen, Bamberg, Germany W. Albrecht KG, Bemberg, Germany Filed: May 24, 1972 Appl. N0.: 256,311

Assignee:

Primary Examiner-Roy Lake Assistant Examiner-J. W. Davie Attorney, Agent, or FirmHane, Baxley & Spiecens [57] ABSTRACT The specification describes a method for the attachment of contact members, held in a base, with electrodes passing through the glass envelope of a miniature incandescent lamp. In accordance with the method the contact members are strips of electrically conducting material which are introduced from below through recesses in the bottom of the upper part of the base until the strips reach the upper rim of the base and are electrically connected with the electrodes. Following this with the introduction of the glass envelope in the hollow cylindrical upper part of the base the strips are drawn back. At their free lower ends they are severed and are fixed to the lower part of the base.

6 Claims, 5 Drawing Figures METHOD OF MANUFACTURING BASE TERMINALS OF A MINIATURE INCANDESCENT LIGHT BULB BACKGROUND or INVENTION 1. Field to which Invention Relates The present invention relates to a method for connecting the electrodes of the glass envelope of incandescent lamps, and more particularly miniature incandescent lamps, with contact members passed through the base.

2. The Prior 'Art The small dimensions of miniature incandescent lamps or'bulbs leads to it being necessary to keep to comparatively small tolerances in lamp assembly so that suitable adjustment devices are necessary. As a result of this and other factors costs of production are comparatively high.

. For this reason it is desirable to make a constant and critical check of the manufacturing operation and to exhaust all possibilities for automation of the manufacturing process, including the connection between the electrodes of the glass envelope and the contact members passed through the lamp base.

I SUMMARY OF INVENTION In accordance with the invention I intend to provide for a simplification and improvement of prior art methods for the production of incandescent lamps, more particularly miniature incandescent lamps. In accordance with one aspect of the invention the contact members comprise strips of electrically conducting material which are introduced from below through recesses in the bottom of thehollow cylindrical upper part of the base over the upper edge of the base and connected with the electrodes in a conducting manner, following which they are drawn back on the introduction of the glass envelope into the hollow cylindrical upper part of the base, their free ends are severed and attached to the lower part of the base.

These method steps can be carried out at least for the most parts automatically, that is to say so as to save costs. Furthermore, incandescent lamps produced in accordance with the invention having improved electrical and mechanical properties.

In accordance with a further development of the invention the contact members have. their ends extending over the upper edge or rim of the base bent round in a hooked manner after the introduction into the base and the contact members are connected by pressing together and/or point welding with the electrodes, so that a good electrical contact is made and at the same time a possibility of adjustment is provided as regards the following method step in accordance with the invention, in which the contact members together with the glass envelope are drawn back so far into the base that their ends bent in the form of hooks strike against the bottom of the upper base part.

Following this in accordance with the invention the free ends of the contact members are fixed on projections arranged on both sides of the bottom part of the base and thus provide a secure anchoring of the contact members.

LIST OF SEVERAL VIEWS OF DRAWINGS Further features, details and advantages of the invention will be gathered from the following description of 2 a preferred embodiment of the invention with reference to the drawing.

FIG. 1 is a view of a lamp or bulb socket or base with the contact members introduced into it. FIG. 2 is a plan view of the arrangement as shown in FIG. 1. FIG. 3 is a section through a swaged foot base in the lower part. FIG. 4 shows the glass envelope and base with the connected contact parts.

FIG. 5 shows the finished lamp after mounting.

DESCRIPTION OF PREFERRED EMBODIMENTS 5 In the figures the individual steps of the method in acl cordance with the invention are represented in the case of a miniature incandescent'bulb or lamp, whose base 1, which is preferably made of plastics material, has a hollow cylindrical upper part 2 with holes 3 in its bottom and a swaged foot base 4 constructed as a flat plug. Two strips 5 and 6 of an electrically conducting material, drawn off for example from supply rolls, are introduced into these holes 3 for forming the contact members so far that their ends 7 and 8 extend for a dis- 2 tance of a few millimeters beyond the upper rim 9 of the base. The projecting ends 7 and 8' of the contact members 5 and 6 are then so deformed, for example to form hooks 10 and 11 that they can serve as a temporary holding means for the terminals 12 and 13, connected with the filament (not shown), in the glass envelope 14. The terminals l2 and 13 are hooked in the hooks 10 and l l and following this the contact parts on both sides are connected with each other so as to produce afirm mechanicalconnection with a good electrical conductivity, for exampleby swaging and point welding. I

After the connection of these parts 10, ll, 12 and 13 the glass envelope and the contact parts are introduced into the cylindrical upper part 2 0f the base until the hooks 10 and 11 strike against its bottom 15. The protruding free ends 16 and 17 of the contact members 5 and 6 are then shortened so that they have the length which is required and before or after this cutting operation they can be attached to the lower part of the base. 45

The lower part4 of the base which as previously stated is in the form of a flat plug, may be tapered towards its lower end in order to facilitate insertion into a lamp socket and is divided by a partition 18 into two branches l9 and 20. Each of these branches has a lateral recess 21, in which the respective ends 16 and 17 of the contact members 5 and 6, bent around the branches l9 and 20, are fixed.

The invention thus provides a simple and reliable connection with good conducting properties between the electrodes'of the'glass envelope and the contact members of the lamp base.

I claim:

1. A method of manufacturing base terminals of a miniature incandescent light bulb having filament terminals extending through the envelope of the bulb and a base having a hollowed upper portion for accommodating therein at least part of the envelope and a flat 65 lower portion for mounting base terminals thereon, the

upper base portion including a bottom having holes therethrough for the passage of conductors, said method comprising the steps of:

inserting electrically conducting pliable strips through said bottom holes in the upper base portion into positions in which the strips protrude from the upper rim of the hollowed base portion;

then deforming strip portions for temporarily retaining the strips in said protruding positions;

then mechanically and electrically connecting the strips at the protruding ends thereof to the filament terminals;

then withdrawing the strips from below the base portion until the bulb and its filament terminals are seated within the upper base portion; and

finally bending strip portions protruding from the lower base portion back upon the outside of said portion to constitute contact terminals on the lower base portion.

2. The method of claim 1 and comprising the step of bending the protruding strip portions so as to form hook-shaped configurations having a general outline wider than the holes thereby retaining the strips in said protruding positions.

3. The method of claim 2 wherein said filament terminals are mechanically and electrically joined to the strips by swaging.

4. The method of claim 2 wherein said filament terminals are mechanically and electrically joined to the strips by spot welding.

5. The method according to claim 1 and comprising the step of bending the protruding strip portions so as to form hook-shaped configurations having a general outline wider than the holes thereby retaining the strips in said protruding positions, and withdrawing said strips until the hook-shaped portions thereof abut against the bottom of the upper base portion.

6. The method according to claim 1 and comprising the step of providing spaced-apart protrusions on the outside of the fiat base portion and securing the bentback strip portions protruding from the base portion to said protrusions. 

1. A method of manufacturing base terminals of a miniature incandescent light bulb having filament terminals extending through the envelope of the bulb and a base having a hollowed upper portion for accommodating therein at least part of the envelope and a flat lower portion for mounting base terminals thereon, the upper base portion including a bottom having holes therethrough for the passage of conductors, said method comprising the steps of: inserting electrically conducting pliable strips through said bottom holes in the upper base portion into positions in which the strips protrude from the upper rim of the hollowed base portion; then deforming strip portions for temporarily retaining the strips in said protruding positions; then mechanically and electrically connecting the strips at the protruding ends thereof to the filament terminals; then withdrawing the strips from below the base portion until the bulb and its filament terminals are seated within the upper base portion; and finally bendIng strip portions protruding from the lower base portion back upon the outside of said portion to constitute contact terminals on the lower base portion.
 2. The method of claim 1 and comprising the step of bending the protruding strip portions so as to form hook-shaped configurations having a general outline wider than the holes thereby retaining the strips in said protruding positions.
 3. The method of claim 2 wherein said filament terminals are mechanically and electrically joined to the strips by swaging.
 4. The method of claim 2 wherein said filament terminals are mechanically and electrically joined to the strips by spot welding.
 5. The method according to claim 1 and comprising the step of bending the protruding strip portions so as to form hook-shaped configurations having a general outline wider than the holes thereby retaining the strips in said protruding positions, and withdrawing said strips until the hook-shaped portions thereof abut against the bottom of the upper base portion.
 6. The method according to claim 1 and comprising the step of providing spaced-apart protrusions on the outside of the flat base portion and securing the bent-back strip portions protruding from the base portion to said protrusions. 